i think it's because with him what you see is what you get, right down to the flaws. he's not difficult to figure out, in fact he's just like a normal person who wants to be desirable, popular, successful etc. it's just that he has a lot more drive and he's a lot stronger than you'd realise just by watching him. it's not overt like minho's but, if i can put it like this, key hates losing to life, to circumstances, his metabolism etc.

and in terms of relationships, he's not just concerned or motherly anymore, he's basically hopelessly in love with the lot of them now, particularly onew and minho.